Skeletal muscle cells consume enormous amounts of ATP. From the following list, choose the two proteins that directly hydrolyze most of this ATP. Your answer would be a two-letter string composed of letters A to F only, in alphabetical order, e.g. AF.
A. Troponin complex
B. Ca²⁺-release channel
C. Myosin light chains
D. Myosin heavy chain
E. Myosin light-chain kinase
F. Sarcoplasmic reticulum Ca²⁺-pump